# US 12,603,321 B2 · Battery separators, electrodes, cells, lithium batteries and related methods

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- Number: US 12,603,321 B2
- Document ID: US12603321B2
- Status: Granted
- Kind: B2
- Application number: 16/494,832
- Filed: 2018-03-19
- Published: 2020-02-06
- Granted: 2026-04-14
- Earliest claimed: 2017-03-20
- Assignees: Celgard, LLC
- Applicants: Celgard, LLC
- Inventors: Zhengming Zhang; Weifeng Fang
- Web page: https://patentgrep.com/patent/US12603321B2

## CPC

- H01M 4/13: Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 4/50: of manganese
- H01M 4/52: of nickel, cobalt or iron
- H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 10/052: Li-accumulators
- H01M 10/0567: characterised by the additives
- H01M 50/403: Manufacturing processes of separators, membranes or diaphragms
- H01M 50/406: Moulding; Embossing; Cutting
- H01M 50/489: Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
- H01M 50/491: Porosity
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- H01M 2004/028: {Positive electrodes}
- H01M 2300/0051: Carbonates
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An improved battery separator and an energy cell comprising the improved battery separator are provided. The improved battery separator comprises a porous membrane having at least one of the following properties when wet with electrolyte: has no or low volume; has no or low mass; soaks as much liquid electrolyte as possible; blocks or removes any harmful substances in the electrolyte; never melts at any high temperature; does not react with the cathode or the anode under any conditions; has a mechanical strength equal to or greater than steel; is an electronic insulator under any conditions; and blocks metal dendrite growth.

## Claims

### Claim 1

A battery separator comprising a dry process porous membrane comprising polyethylene and having pores having an average pore size of less than 1 micron, wherein the dry-process porous membrane comprises multiple layers which are co-extruded wherein each layer has a thickness from 0.1 to 0.9 microns, wherein the pores are formed via this dry process and are subsequently filled with an ionic conductive medium, wherein the ionic conductive medium comprises gel electrolyte, and wherein the separator has a JIS Gurley of 75 to 300, wherein the dry process porous membrane contains no residual solvent or processing oil, and wherein the separator conducts lithium ions when dry (no electrolyte).

### Claim 2 (depends on 1)

The battery separator of claim 1, wherein the separator has a JIS Gurley of 100 to 300.

### Claim 3 (depends on 1)

The battery separator of claim 1, wherein the battery separator is macroporous, microporous, or nanoporous.

### Claim 4 (depends on 1)

The battery separator of claim 1, wherein the separator conducts lithium ions when wet with electrolyte.

### Claim 5 (depends on 1)

The battery separator of claim 1, wherein the separator when wet with electrolyte, does not react with a cathode or an anode.

### Claim 6 (depends on 1)

The battery separator of claim 1, wherein the separator when wet with electrolyte is an electric insulator.

### Claim 7 (depends on 1)

The battery separator of claim 1, wherein the separator has a porosity of 40% to 70%.

### Claim 8 (depends on 3)

The separator of claim 3, wherein the battery separator is macroporous.

### Claim 9 (depends on 3)

The battery separator of claim 3, wherein the battery separator is nanoporous.

### Claim 10 (depends on 1)

The battery separator of claim 1, wherein the electrolyte further comprises an electrolyte additive, wherein the electrolyte additive comprises at least one selected from the group of a SEI improving agent selected from the group of EC (vinyl ethylene carbonate), FEC (fluoroethylene carbonate), and LiBOB (Lithium bis (oxalato) borate); a cathode protection agent selected from the group consisting of N,N′-dicyclohexylcarbodiimide, N,N-diethylamino trimethylsilane, and LiBOB; a flame retardant additive selected from the group of TTFP (tris (2,2,2-trifluoroethyl) phosphate), fluorinated propylene carbonates, and MFE (methyl nonafluorobuyl ether); a LiPF6 salt stabilizer selected from the group of LiF, TTFP (tris (2,2,2-trifluoroethyl) phosphite), fluorinated carbamate, and hexamethyl-phosphoramide; an overcharge protector selected from the group of xylene, cyclohexylbenzene, biphenyl, 2,2-diphenylpropane, and phenyl-tert-butyl carbonate; an aluminum corrosion inhibitor selected from the group of LiBOB, LiODFB, and borate salts; a lithium deposition agent or improver selected from the group of AlI3, SnI2, cetyltrimethylammonium chlorides, perfluoropolyethers, and tetraalkylammonium chlorides with a long alkyl chain; a solvation enhancer selected from the group of 12-crown-4, and TPFPB (tris (pentafluorophenyl)); a wetting agent comprising cyclohexane; and a viscosity diluter comprising cyclohexane.